This attribute specifies the rfc1483 encapsulation type to be used for
the AtmConnections under this AtmMpe. Specifying llcEncap
allows multiplexing of multiple protocols over the VCCs. The
protocol of the carried PDU will be identified by an IEEE 802.2
Logical Link Control header. If Bridging or Inverse ARP is to be
carried over a VCC, llcEncap must be used. Specifying ipVcEncap
or ipxVcEncap indicates that all the VCCs (i.e. AtmConnections)
under an AtmMpe component will use VC based multiplexing and
will carry IP or IPX PDUs only. Thus an IpxPort cannot be
provisioned under a protocol port linked to an AtmMpe component
with encapsulation type of ipVcEncap. Similarly, an IpPort cannot
be provisioned under a protocol port linked to an AtmMpe
component with encapsulation type of ipxVcEncap.